Yarn handling pneumatic device

ABSTRACT

A yarn handling pneumatic device including a casing having a distribution chamber therein, a delivery conduit adapted to pick up yarn at one end to move the yarn through a delivery tube and an egress tube co-axially aligned in the device to a yarn collecting device, and a lever for pivotally sliding the egress tube to therefore control the area of a control orifice defined between the outlet of the delivery tube and the inlet lip of the egress tube in the distribution chamber, the inlet lip having an inner surface configuration defined by a surface of revolution having an arcuate generatrix with a point of inflexion. The egress tube is advanced toward the delivery tube to define a restricted position for initially introducing yarn into the pneumatic device and is thereafter moved away from the delivery tube to increase traction on the yarn as it passes through the pneumatic device. In a modification of the yarn handling pneumatic device a cutting mechanism is provided therein to selectively cut yarn passing therethrough.

United States Patent Juppet [54] YARN HANDLING PNEUMATIC DEVICE [72] Inventor: Paul Juppet, Lyon, France [73] Assignee: Societe Rhodiaceta, Paris, France [22] Filed: April 13, 1971 [21] App]. No.: 133,579

[30] Foreign Application Priority Data April 16, 1970 France ..7013708 [52] US. Cl. ..83/100, 83/198, 83/402,

[51] Int. Cl. ..B26d 7/06 [58] Field of Search ..28/l.4; 226/97.7; 83/100 [56] References Cited UNITED STATES PATENTS 3,094,262 6/1963 Ashby et a1 ..226/97 3,156,395 11/1964 Ashby et al ..226/7 Primary Examiner-Allen N. Knowles Assistant ExaminerGene A. Church Attorney-Sherman and Shalloway Aug. 15, 1972 [5 7] ABSTRACT A yarn handling pneumatic device including a casing having a distribution chamber therein, a delivery conduit adapted to pick up yarn at one end to move the yarn through a delivery tube and an egress tube co-axially aligned in the device to a yarn collecting device, and a lever for pivotally sliding the egress tube to therefore control the area of a control orifice defined between the outlet of the delivery tube and the inlet lip of the egress tube in the distribution chamber, the inlet lip having an inner surface configuration defined by a surface of revolution having an arcuate generatrix with a point of inflexion. The egress tube is advanced toward the delivery tube to define a restricted position for initially introducing yarn :into the pneumatic device and is thereafter moved away from the delivery tube to I increase traction on the yarn as it passes through the pneumatic device. In a modification of the yarn handling pneumatic device a cutting mechanism is provided therein to selectively cut yarn passing therethrough.

16 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention pertains to pneumatic devices for handling yarn and, more particularly, to such devices for use in handling yarn at high speeds.

2. Discussion of the Prior Art Yarn handling pneumatic devices, sometimes referred to as pneumatic guns, have a great number of uses in the textile industry such as in the initial starting of process machines and to facilitate yarn transfer and shifting of spools. For instance, the yarn delivered at high speed from an extruder must be conveyed at this same speed to a drawing device which is rotating at high speed, and yarn handling pneumatic devices are utilized to maintain the yarn under tension during movement from the extruder to the drawing device at the initiation of operation of the process or to continuously supply the yarn to any suitable yarn collection device. Other applications for yarn handling pneumatic devices include the passage of yarn from one side of a textile machine to the other, the guiding of a yarn or of several yarns along an extended varying path and in most instances where yarn must follow a sinious path from one treating device to another.

[1.5. Pats. Nos. 2,677,964, 3,094,262 and 3,156,395 are illustrative of prior art pneumatic devices utilized for yarn handling; however, the pneumatic devices of these patents have the disadvantages of not operating satisfactorily when used for yarn moving at speeds of 2,000 meters per minute. The primary reasons for the failure of these pneumatic devices to properly handle yarn moving at high speeds are that the devices either exert insufficient traction on the yarn as it is moving through the device or they do not provide adequate suction to grip the yarn. Furthermore, the prior art devices normally operate with high air outputs and pressure which render them expensive to manufacture and difficult to manage while still failing to provide the required performance.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to construct a pneumatic device capable of handling yarns moving at high speeds.

The present invention is generally characterized in a yarn handling pneumatic device having a distribution chamber for receiving compressed air, delivery means having an outlet disposed in the distribution chamber, and a movable egress tube having an inlet disposed in the distribution chamber adjacent the outlet of the delivery means, the improvement comprising a lip for the inlet of the egress tube having an inner surface configuration defined by a surface of revolution having an arcuate generatrix with a point of inflexion.

Another object of the present invention is to construct a yarn handling pneumatic device having a movable egress tube therein with an inlet lip having an inner surface configuration defined by a surface of revolution having an arcuate generatrix.

A further object of the present invention is to provide a cutting mechanism in a yarn handling pneumatic device for selectively cutting yarn. passing therethrough.

The present invention has another object in that the knife blade of the cutting mechanism has a bore therethrough to accommodate yarn as it passes through the pneumatic device.

Another object of the present invention is to provide a yarn handling pneumatic device with a delivery conduit, a delivery tube and an egress tube co-axially aligned an presenting symmetry of revolution about the axis along which the yarn travels.

Some of the advantages of the present invention over 'the prior art are that the yarn handling pneumatic device of the present invention may be utilized with high yarn speeds, the pneumatic device provides a cutting mechanism to provide inherent safety when utilized with high titer yarns, and the pneumatic device does not require high air'output and pressure.

Other objects and advantages will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation partially in section of the yarn handling pneumatic device of the present invention.

FIG. 2 is a broken enlarged view of the control orifice of the pneumatic device of FIG. 1.

FIG. 3 is a side elevation partially in section of a modification of the pneumatic device of FIG. 1.

FIG. 4 is a broken view of a control orifice according to another embodiment of the pneumatic device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A yarn handling pneumatic device 10 is illustrated in FIG. 1 and includes a delivery conduit 12 terminating at a yarn pick-up end 14 having a replaceable steel bushing 16 secured therein to reduce friction of the yarn as it enters the pneumatic device. A casing 18 is secured to delivery conduit 12 and defines a distribution chamber 20 adjacent thereto. A delivery tube 22 is co-axially aligned with the bore in delivery conduit 12 and extends therefrom into distribution chamber 20. Delivery tube 22 has a cylindrical neck 24 terminating at an annular outlet 25, and the bore through tube 22 has the same dimensions as the bore through conduit 12 to provide a smooth surface in order not to interfere with the passage of yarn. A slidable yarn egress tube 26 is co-axially aligned with delivery tube 22 and has an inlet lip 28 adapted to cooperate with the annular outlet 25 of delivery tube 22 to provide a control orifice. A leg 30 extends radially from the outer surface of egress tube 26, and a set screw 32 is slidably received in a bore in leg 30 and threadedly engages casing 18. A lever 34 is pivotally mounted by means of a pin 36 on the side of casing 18, and pin 36 carries a protrusion or cam 38 which is received in a notch 40 in the outer surface of egress tube 36.

Compressed air is supplied to distribution chamber 20 through a flexible supply tube 42 which is received in casing 18 to communicate with chamber 20 at one end and extends through a handle extension 44 pivotally mounted on casing 18 at a pin 46. The other end of supply tube 42 is adapted to receive a supply of compressed air from a suitable source not shownv A tube 48 has one end received in a counter bored portion of egress tube 26 in order to provide a smooth surface therein in order not to interfere with the passage of yarn therethrough to any suitable yarn collection device 50 to which the yarn is to be supplied.

The control orifice, that is the area where the downstream end of delivery tube 22 defined by annular outlet 24 meets the upstream end of egress tube 26 defined by inlet lip 28, is more clearly illustrated in FIG. 2. The inner diameter of egress tube 26 is substantially constant along the length thereof with the exception of outlet lip 28. The outlet lip 28 is formed of a ring which is arcuate in cross section and extends from the outer surface at the end of egress tube 26 to the inner surface of egress tube 26 to define an annular knee or protrusion 52 extending radially inwardly from the inner surface to have an inner diameter slightly greater than the diameter of the outer surface of neck 24 at outlet 25 of delivery tube 22. The inner surface of egress tube 26 smoothly terminates in knee portion 52 at 54 in order to permit protrusion 52 to be positioned adjacent the outer surface of delivery tube 22 to facilitate initial pick-up of yarn as will be more fully described hereinafter.

The control orifice has an annular surface area E,, which annular surface area is defined as the area between the outer surface of neck 24 of delivery tube 22 and the point on the arcuate inner surface of inlet lip 28 of egress tube 26 nearest the delivery tube. Thus, it will be appreciated that the annular surface area E is not necessarily transverse to the common axis extending through the pneumatic device but may take the form of the lateral surface of a truncated cone whose generatrix is the segment defined as the nearest point on the inner surface of the inlet lip to the outer surface of neck 24. The cross sectional area of the bore of egress tube 26 is defined as E and the ratio of the areas E /E is preferably in the range between 0.05 and 0.5 and is most advantageously maintained within the range of0.l to 0.3.

In operation yarn 56 is captured at pick-up end 14 by moving lever 34 clockwise looking at FIG. 1 to move egress tube 26 to the left by means of the rotating action of cam 38 in notch 40. With egress tube 26 in this position, the control orifice is restricted to increase the velocity of air passing from distribution chamber 20 into egress tube 26. Therefore, in accordance with Bernoullis Principal the pressure at the downstream end of the delivery means is substantially reduced to create a suction pulling yarn 56 into delivery conduit 32. The yarn 56 is thereby introduced into pneumatic device 10; and, once the yarn is adequately engaged, the force on lever 34 is released to permit the pressure from the compressed air in distribution chamber 20 to move egress tube 26 to the right to abut the head of set screw 32 which acts as a stop. The area of the control orifice will accordingly be increased to permit a greater flow of air therethrough to thereby provide considerable traction to grip the yarn 56 and move the yarn through the pneumatic device 10 to yarn collection device 50. Set screw 32 may be rotated to control the area E, of the control orifice to permit variation of the traction force on the yarn preferably near to but less than the maximum load the yarn can withstand.

A modification of the yarn handling pneumatic device of FIG. 1 is illustrated in FIG. 3 and components in the pneumatic device of FIG. 3 which are identical to components of the pneumatic device of FIG. 1 are given identical reference numbers and are not described again.

The primary difference between the pneumatic devices of FIGS. 1 and 3 is that the pneumatic device of FIG. 3 is provided with a cutting mechanism in order to permit handling of high titer yarns, which yarns are quite strong thereby requiring the cutting mechanism to protect the operator. The pneumatic device of FIG. 1 is preferably utilized for handling fine titer yarns since in the handling of such yarns it is preferable to utilize a stationary yarn transfer device having a cutting mechanism in that the risk of a dangerous accident is negated due to the low strength of the yarn. Since the pneumatic device of FIG. 1 does not have a cutting mechanism therein, it will be appreciated that the cost thereof is reduced as well as the weight of the device.

The handle extension 44 of the pneumatic device of FIG. 3 operates as a grip to control the operation of the cutting mechanism, and an elongated strip 58 is secured thereto by means of a screw 60 and runs longitudinally along casing 18 to engage a plate 62 disposed in a chamber 64 on the other side of distribution chamber 20. A coil spring 66 is mounted in compression between plate 62 and a wall of chamber 64, and a rod 68 is attached to plate 62 and extends through the chamber and a wall thereof to engage a ball valve member 70 which cooperates with an annular valve seat 72 to control flow of compressed air from distribution chamber 20 through a conduit 74 to a chamber 76. Chamber 76 is bounded on one side by a flexible diaphragm 78 which engages an end of a piston knife blade 80. Knife blade 80 is movable transversely to the direction of movement of yarn 56 through the pneumatic device and cooperates with a knife blade 82 to control the cutting of the yarn. Knife blades 80 and 82 are supported by 84 and 86, and are pressed close to each other by an elastic washer not shown and a leaf spring 88 has a bent end engaging the free end of knife blade 80 to bias the knife blade toward the non-cutting position illustrated in FIG. 3. The knife blades 80 and 82 are advantageously disposed within the delivery means and each has a bore aligned with the bores in delivery conduit 12 and delivery tube 22 such that the yarn is surrounded on all sides.

The operation of the pneumatic device of FIG. 3 is the same as that described with respect to the pneumatic device of FIG. 1 with the exception, of course, of the cutting mechanism. The movement of knife blade 80 is controlled ultimately by the pivotal movement of handle extension 44 in that when extension 44 is released, spring 66 will force plate 62 toward the pickup end of the pneumatic device to accordingly move extension 44 to a position abutting casing 18 by means of strip 58. The compressed air in distribution chamber 20 will, accordingly, force ball valve member 70 away from valve seat 72 to provide a high pressure in chamber 76. This pressure moves diaphragm 78 down to provide a cutting movement to knife blade 80 relative to knife blade 82 with piston-like action. Thus, it will be appreciated that if an operator releases extension 44 for any reason, the cutting mechanism will be 5 automaticaiiv operated to cut the yarn passing through the pneumatic device to thereby prevent inadvertent damage.

When the operator initially picks up the yarn 56, he must grip handle extension 44 to pivot the same counterclockwise thereby forcing ball valve member 70 against valve seat 72 and permitting spring 88 to return knife blade 8% to the position illustrated in FIG. 3. Yarn pick-up is then accomplished by manipulation of lever 34 as described with reference to the pneumatic device of H6. 1. and the control orifice is set when lever 34 is released. When it is desired to cut the yarn passing through the pneumatic device, handle extension 44 is released to pivot counterclockwise and permit movement of ball valve member 70 away from valve seat 72 to supply pressure to chamber 76 and move knife blade 30 as above described. As long as handle extension 44 is released, knife blade 80 will block the passage of yarn through the pneumatic device to prevent the introduction of further yarn therein regardless of the position of egress tube 26.

Another embodiment of the pneumatic device of the present invention is illustrated partially in FIG. 4, it being realized that the components to be utilized with the structure of FIG. 4 are identical to those of either H65. 1 or 3 with the exception of the inner surface configuration of egress tube 26. In the embodiment of FIG. 3 egress tube 26 is provided with an inlet lip 90 which has an inner surface configuration defined by an arcuate segment bent in opposite directions in S-like fashion. Accordingly, the inner surface of inlet lip 90 includes a concave curved surface 92 which smoothly joins a convex curved surface 94, and the inner surface configuration is formed as a surface of revolution having a doublebend generatrix, that is a generatrix consisting of convex and concave curves. The embodiment of FIG. 4 may be utilized with the embodiments of H68. 1 or 3 in the same manner as described above.

With reference to the above description it will be appreciated that the terms upstream" and downstream" are used relative to the direction of movement of the yarn through the pneumatic device, and the term yarn" is meant to include any continuous filament or assembly of continuous filaments including, but not limited to, viscose yarn, secondary cellulose acetate, cellulose triacetate, polyamide, polyester, polyolefin, acrylic or modacrylic yarns, vinyl polymer yarns, glass yarns and industrial cable.

The pneumatic device of the present invention is preferably constructed of plastic to decrease corrosion and weight and avoid scoring of the surfaces of the rotating elements of textile machines upon accidental contact therewith.

in one application of the principal of the present invention a yarn handling pneumatic device according to F IG. 1 was constructed of Nylon 66 such that the ratio Ti /E was variable within a range of 0. 14 to 0.28 within the extreme positions of movement of egress tube 26. The device so constructed was utilized for the transfer of a 71 citex/33 filaments yarn of polyhexamethylene adipamide moving at a velocity of 3,000 m/min while maintaining a 37 gram tension on the yarn. The compressed air was supplied at 76 normal m /hour and a pressure of S l pascals. It will be appreciated from the above that the pneumatic device of the present invention provides increased traction force over prior art pneumatic devices primarily due to the specific configuration of the inlet lip of the movable egress tube 26.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, all matter described above or shown in the accompanying drawings is intended to be interpreted as illustrative and not in a limiting sense.

lclaim:

1. In a yarn handling pneumatic device including a distribution chamber for receiving compressed air, delivery means having an outlet disposed in said distribution chamber, and a movable egress tube having an inlet disposed in said distribution chamber adjacent said outlet of said delivery means, the improvement comprising a lip for said inlet of said egress tube having an inner surface configuration defined by a surface of revolution having an arcuate generatrix with a point of infiexion.

2. The improvement as recited in claim 1 wherein said inner surface of said inlet of said egress tube protrudes toward the center of said egress tube.

3. The improvement as recited in claim 1 wherein said inner surface of said inlet of said egress tube has first and second opposite curves.

4. The improvement as recited in claim 3 wherein said first curve is concave and terminates at the end of said egress tube and said second curve is convex and extends from said first curve in an S-like configuration.

5. The improvement as recited in claim 1 wherein the area between said inner surface of said egress tube and the outer surface of said outlet of said delivery means provides a control orifice area defined as E said egress tube has a substantially constant inner diameter providing a cross sectional area defined as E and the ratio E,/E is within a range of 0.05 to 0.5.

6. The improvement as recited in claim 1 wherein the area between said inner surface of said egress tube and the outer surface of said outlet of said delivery means provides a control orifice area defined as E,, said egress tube has a substantially constant inner diameter providing a cross sectional area defined as E and the ratio E,/E is within a range of0.l to 0.3.

7. The improvement as recited in claim 1 wherein said delivery means includes a cutting mechanism having a knife blade movable transversely to movement of the yarn through said pneumatic device to cut the yarn.

8. The improvement as recited in claim 7 wherein said knife blade has a bore therein and the yarn is adapted to pass through said bore.

9. The improvement as recited in claim 8 wherein said cutting mechanism includes a second chamber, valve means controlling communication between said distribution chamber and said second chamber, a diaphragm defining one wall of said second chamber and engaging said knife blade to control movement thereof, and operating means for controlling said valve means to control the cutting of yarn.

10. The improvement as recited in claim 9 wherein said control means includes a strap having a first end operating said valve means and a second end and further comprising a casing surrounding said egress tube and a handle extension pivotally mounted on said casing, said second end of said strap being attached to said handle extension whereby pivotal movement of said handle extension controls said cutting mechanism.

l l. The improvement as recited in claim 10 wherein said egress tube has a notch in the center surface thereof and further comprising a lever pivotally supported on said casing, a cam movable by said lever and engaging said notch to control movement of said egress tube.

12. The improvement as recited in claim 11 and further comprising a set screw threadedly engaging said casing and said egress tube has a leg extending therefrom slidably engaging said set screw whereby said set screw limits movement of said egress tube by abutment of said leg against said set screw.

13. The improvement as recited in claim 1 wherein said outlet of said deliverymeans has a neck with a cylindrical outer surface.

14. The improvement as recited in claim 1 wherein said delivery means, said egress tube, and said distribution chamber are coaxially aligned.

15. The improvement as recited in claim 1 and further comprising a casing surrounding said egress tube and defining therewith said distribution chamber, and control means supported on said casing for moving said egress tube.

16. The improvement as recited in claim 15 wherein said control means includes a lever pivotally mounted on said casing and a cam movable with said lever, and said egress tube has a notch in the outer surface thereof receiving said cam whereby movement of said lever controls movement of said egress tube. 

1. In a yarn handling pneumatic device including a distribution chamber for receiving compressed air, delivery means having an outlet disposed in said distribution chamber, and a movable egress tube having an inlet disposed in said distribution chamber adjacent said outlet of said delivery means, the improvement comprising a lip for said inlet of said egress tube having an inner surface configuration defined by a surface of revolution having an arcuate generatrix with a point of inflexion.
 2. The improvement as recited in claim 1 wherein said inner surface of said inlet of said egress tube protrudes toward the center of said egress tube.
 3. The improvement as recited in claim 1 wherein said inner surface of said inlet of said egress tube has first and second opposite curves.
 4. The improvement as recited in claim 3 wherein said first curve is concave and terminates at the end of said egress tube and said second curve is convex and extends from said first curve in an S-like configuration.
 5. The improvement as recited in claim 1 wherein the area between said inner surface of said egress tube and the outer surface of said outlet of said delivery means provides a control orifice area defined as E1, said egress tube has a substantially constant inner diameter providing a cross sectional area defined as E2, and the ratio E1/E2 is within a range of 0.05 to 0.5.
 6. The improvement as recited in claim 1 wherein the area between said inner surface of said egress tube and the outer surface of said outlet of said delivery means provides a control orifice area defined as E1, said egress tube has a substantially constant inner diameter providing a cross sectional area defined as E2, and the ratio E1/E2 is within a range of 0.1 to 0.3.
 7. The improvement as recited in claim 1 wherein said delivery means includes a cutting mechanism having a knife blade movable transversely to movement of the yarn through said pneumatic device to cut the yarn.
 8. The improvement as recited in claim 7 wherein said knife blade has a bore therein and the yarn is adapted to pass through said bore.
 9. The improvement as recited in claim 8 wherein said cutting mechanism includes a second chamber, valve means controlling communication between said distribution chamber and said second chamber, a diaphragm defining one wall of said second chamber and engaging said knife blade to control movement thereof, and operating means for controlling said valve means to control the cutting of yarn.
 10. The improvement as recited in claim 9 wherein said control means includes a strap having a first end operating said valve means and a second end and further comprising a casing surrounding said egress tube and a handle extension pivotally mounted on said casing, said second end of said strap being attached to said handle extension whereby pivotal movement of said handle extension controls said cutting mechanism.
 11. The improvement as recited in claim 10 wherein said egress tube has a notch in the center surface thereof and further comprising a lever pivotally supported on said casing, a cam movable by said lever and engaging said notch to control movement of said egress tube.
 12. The improvement as recited in claim 11 and further comprising a set screw threadedly engaging said casing and said egress tube has a leg extending therefrom slidably engaging said set screw whereby said set screw limits movement of said egress tube by abutment of said leg against said set screw.
 13. The improvement as recited in claim 1 wherein said outlet of said delivery means has a neck with a cylindrical outer surface.
 14. The improvement as recited in claim 1 wherein said delivery means, said egress tube, and said distribution chamber are coaxially aligned.
 15. The improvement as recited in claim 1 and further comprising a casing surrounding said egress tube and defining therewith said distribution chamber, and control means supported on said casing for moving said egress tube.
 16. The improvement as recited in claim 15 wherein said control means includes a lever pivotally mounted on said casing and a cam movable with said lever, and said egress tube has a notch in the outer surface thereof receiving said cam whereby movement of said lever controls movement of said egress tube. 